The scientific method, developed in the 17th century, is a way of problem-solving by making a hypothesis and then testing it, a way of thinking that values observation and data instead of fanciful ideas about the order of things.
The scientific method is something that probably seems pretty obvious to you, because nowadays, everyone uses it. If you think that eating apples might cure depression, that's a hypothesis. Round up your saddest friends, make them eat apples for a month, and see if it works. Doing experiments to test hypotheses is the foundation of the scientific method. A successful experiment doesn't mean you necessarily found the be-all-end-all truth, but the method helped you get closer to it.